Reticle pod having side containment of reticle

ABSTRACT

A reticle pod includes an outer pod, an inner pod cover and an inner base plate. A reticle is supported on the base and is contained within the environment created by the inner pod cover and the inner pod base. The inner pod cover can include a plurality of reticle retainers configured to contact a side wall of the reticle and limit movement of the reticle in a horizontal direction.

PRIORITY

This application claims the benefit of U.S. Provisional Application Ser.No. 62/380,377, filed Aug. 27, 2016, entitled “RETICLE POD HAVING SIDECONTAINMENT OF RETICLE,” U.S. Provisional Application Ser. No.62/405,518, filed Oct. 7, 2016, entitled “RETICLE POD HAVING SIDECONTAINMENT OF RETICLE,” and U.S. Provisional Application Ser. No.62/422,229, filed Nov. 15, 2016, entitled “RETICLE POD HAVING SIDECONTAINMENT OF RETICLE” each of these applications being incorporatedherein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to containers for storing,transporting, shipping and/or processing fragile devices such asphotomasks, reticles and wafers. More particularly, the presentdisclosure relates to a dual containment pod for reticles having aninner pod incorporating a reticle retainer that limits or restrictsmovement in a horizontal direction in an effort to minimize particlegeneration within the pod.

BACKGROUND

One of the process steps commonly encountered in the fabrication ofintegrated circuits and other semiconductor devices is photolithography.Broadly, photolithography involves selectively exposing a speciallyprepared wafer surface to a source of radiation using a patternedtemplate to create an etched surface layer. Typically, the patternedtemplate is a reticle, which is a very flat glass plate that containsthe patterns to be reproduced on the wafer. For example, the wafersurface may be prepared by first depositing silicon nitride on itfollowed by a coating of a light-sensitive liquid polymer orphotoresist. Next, ultraviolet (UV) light is shone through or reflectedoff a surface of a mask or reticle to project the desired pattern ontothe photoresist-covered wafer. The portion of the photoresist exposed tothe light is chemically modified and remains unaffected when the waferis subsequently subjected to a chemical media that removes the unexposedphotoresist leaving the modified photoresist on the wafer in the exactshape of the pattern on the mask. The wafer is then subjected to an etchprocess that removes the exposed portion of the nitride layer leaving anitride pattern on the wafer in the exact design of the mask. Thisetched layer, singly or in combination with other similarly createdlayers, represent the devices and interconnects between devicescharacterizing the “circuitry” of a particular integrated circuit orsemiconductor chip.

With EUV, reflection from the patterned surface is used as opposed totransmission through the reticle characteristic of deep ultravioletlight photolithography. Consequently, the reflective photomask (reticle)employed in EUV photolithography is susceptible to contamination anddamage to a far greater degree than reticles used in conventionalphotolithography. Unnecessary and unintended contact between the reticleand other surfaces during manufacturing, processing, shipping, handling,transport or storage is undesirable in view of the susceptibility of thereticle's delicate features to damage due to sliding friction and/orabrasion.

SUMMARY OF THE INVENTION

The present disclosure relates generally to containers for storing,transporting, shipping and/or processing fragile devices such asphotomasks, reticles and wafers, and more particularly to a dualcontainment reticle pod having an inner pod incorporating a reticleretainer that limits or restricts movement in the X and Y directions inan effort to minimize particle generation within the pod. The reticleretainers, as described herein are configured to contact a side wall ofthe reticle housed within the inner pod and, in some cases, minimize theamount of load that is applied to a top surface of the reticle in a Zdirection.

In some embodiments, a reticle pod for holding a reticle includes: abase configured to support a reticle thereon; a cover having a topsurface and configured to mate with the base; and one or more reticleretainers each including a reticle contact member configured to contacta side wall of a reticle to limit movement of the reticle. Each reticlecontact member includes an outwardly extending arm and a downwardlyextending leg that extends through the cover, wherein upon actuation ofthe arm, the downwardly extending leg is configured to move in adirection toward a side wall of a reticle. In one embodiment, thereticle pod can be contained within an outer pod having an outer podbase and an outer pod cover configured to mate with the outer pod base.The outer pod cover includes an inner surface and at least one contactpad extending from the inner surface such that it contacts and actuatesthe outwardly extending arm of the reticle pod when the reticle pod iscontained within the outer pod causing the downwardly extending leg tomove in a direction toward the side wall of the reticle.

In other embodiments, a method of retaining a reticle includes:receiving a reticle on a base having features configured to support thereticle thereon; placing a cover on the base including the reticle todefine an inner pod, the cover including one or more reticle retainerseach including a reticle contact member, each reticle contact memberincluding an outwardly extending arm that is extends at least partiallyabove the top surface of the cover and a downwardly extending leg thatextends through the cover; and limiting movement of the reticle.

BRIEF DESCRIPTION OF THE DRAWING

The disclosure may be more completely understood in consideration of thefollowing description of various illustrative embodiments in connectionwith the accompanying drawings, in which:

FIG. 1 is an isometric view of an exemplary reticle pod.

FIG. 2 is a cross-sectional view the reticle pod shown in FIG. 1 takenalong line 2-2.

FIG. 3 is an exploded view of the reticle pod shown in FIG. 1.

FIG. 4 is close-up, cross-sectional view of an inner pod including areticle retainer in accordance with an embodiment of the disclosure.

FIG. 5 is close-up, cross sectional view of an inner pod including areticle retainer in accordance with another embodiment of thedisclosure.

FIG. 6A is a close-up view of an inner pod including another reticleretainer provided on an inner surface of an inner pod cover inaccordance with another embodiment of the disclosure.

FIG. 6B is a schematic, cross-sectional view of the reticle retainershown in FIG. 6A.

FIG. 7 is a schematic, partial cross-sectional view of an inner pod withthe cover removed including yet another reticle retainer in accordancewith an embodiment of the disclosure.

FIG. 8 is a schematic, cross-sectional view of an inner pod showinganother reticle retainer in accordance with yet another embodiment ofthe disclosure.

FIG. 9A shows a schematic view a portion of a bottom plate having asocket configured to receive a link.

FIG. 9B shows a schematic view of a link configured to be receivedwithin the socket shown in FIG. 9A.

FIGS. 10A-10D show the reticle retainer of FIG. 8 in operation.

FIG. 11 is a schematic, cross-sectional view of an inner pod showingstill another reticle retainer in accordance with an embodiment of thedisclosure.

FIG. 12A shows a schematic view of an inner pod cover according to anembodiment of the disclosure.

FIG. 12B is a close-up schematic view of a top of a reticle retaineraccording to an embodiment of the disclosure.

FIG. 12C is a schematic, partial cross-sectional view of a reticleretainer according to an embodiment of the disclosure.

FIG. 13 is a perspective view of an inner pod according to yet anotherembodiment of the disclosure.

FIGS. 14A and 14B are close-up, perspective views of a top portion of areticle retainer according to another embodiment of the disclosure.

FIGS. 15A-15C show various views of a reticle contact member accordingto an embodiment of the disclosure.

FIGS. 16A and 16B show top and bottom perspective views of a cap whichforms a portion of the reticle retainer according to an embodiment ofthe disclosure.

FIGS. 17A and 17B are partial, side cross-sectional views of the innerpod showing the reticle retainer in a first position and a secondposition.

FIG. 18 is a perspective view of an inner pod in accordance with anembodiment of the disclosure.

FIG. 19 is a close-up, schematic view of a portion of the reticleretainer in accordance with an embodiment of the disclosure.

FIGS. 20A and 20B show different views of a reticle contact member inaccordance with an embodiment of the disclosure.

FIGS. 21A and 21B show top and bottom perspective views of a cap whichforms a portion of the reticle retainer in accordance with an embodimentof the disclosure.

FIGS. 22A and 22B show top and bottom perspective views of a cap whichforms a portion of the reticle retainer in accordance with anotherembodiment of the disclosure.

FIGS. 23A and 23B are partial, side cross-sectional views of the innerpod showing the reticle retainer in a first position and a secondposition.

FIG. 24 is a partial cross-sectional view of a reticle pod assemblyshowing an inner pod disposed within an outer pod.

FIG. 25 is a simplified, perspective view of the inner pod shown in FIG.18.

FIG. 26 is a perspective view of an inner pod in accordance with yetanother embodiment of the disclosure.

FIGS. 27 and 28 are cross-sectional views of a portion of the inner podshown in FIG. 26.

FIGS. 29A-29C are different views of a reticle retainer in accordancewith yet another embodiment of the disclosure.

While the disclosure is amenable to various modifications andalternative forms, specifics thereof have been shown by way of examplein the drawings and will be described in detail. It should beunderstood, however, that the intention is not to limit aspects of thedisclosure to the particular illustrative embodiments described. On thecontrary, the intention is to cover all modifications, equivalents, andalternatives falling within the spirit and scope of the disclosure.

DETAILED DESCRIPTION

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” include plural referents unless the contentclearly dictates otherwise. As used in this specification and theappended claims, the term “or” is generally employed in its senseincluding “and/or” unless the content clearly dictates otherwise.

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The detailed description and the drawings, which are notnecessarily to scale, depict illustrative embodiments and are notintended to limit the scope of the invention. The illustrativeembodiments depicted are intended only as exemplary. Selected featuresof any illustrative embodiment may be incorporated into an additionalembodiment unless clearly stated to the contrary.

FIGS. 1-3 show various views an exemplary reticle pod 10 for storing andtransporting a reticle or mask 12. The reticle pod 10 may be sometimesreferred to as a dual containment pod or an EUV pod, and may share somesimilar features with the reticle pod shown and described in U.S. Pat.No. 8,613,359 which is incorporated herein by reference in its entiretyfor all purposes. The term reticle may be used to refer to quartzblanks, photo-masks, EUV masks, and other masks that may be used in thesemiconductor manufacturing industry that are susceptible to damage fromparticulates and other matters. In some cases, the reticle 12 may besubstantially square in shape, and may be etched with the desiredcircuit pattern (not depicted). While the disclosed reticle pod 10 isdescribed with reference to a generally square shaped reticle, it willbe generally understood by those of skill in the art that reticles ofother shapes such as for example, a rectangular, polygonal or circularshaped reticle, may be used.

As can be seen in FIGS. 1-3, the reticle pod 10 includes an outer pod 11including an outer pod cover 14 that is configured to mate with an outerpod base 18 enclosing an inner pod 15 which in turn holds the reticle12. The inner pod 15 includes an inner pod cover 26 configured to matewith an inner pod base 32 to form a sealed environment in which thereticle 12 is contained. The outer pod cover 14 can include one or morecontact pads or protrusions provided on an inner surface that areconfigured to contact and apply a downward pressure to a correspondingreticle retainer provided in the cover of the inner pod. Additionally,in some cases, the outer pod cover 14 may include an optional roboticflange 22 which facilitates the automated transportation of the reticlepod 10 throughout a fabrication facility.

Referring now to FIG. 3, the inner pod base 32 has a size and shapegenerally conforming to the size and the shape of the reticle 12, andsupports the reticle 12 when the reticle 12 is contained within theinner pod. The inner pod base 32 includes opposing first and secondmajor parallel surfaces 34 and 36 and four radiused corners 38, anddefines a continuous contact sealing surface 42 near the perimeter offirst major surface 34. In one example, the entire first major surface34 can be provided with a uniform and highly polished surface finish,but this is not required.

In some cases, as shown in FIG. 3, the inner pod base 32 can include apair of reticle guides 46 and a reticle contact 48 located in each ofthe four corners 38 of the base 32. Such reticle guides and reticlecontacts are shown and described in greater detail in U.S. Pat. No.8,613,359, which is incorporated herein by reference. The reticle guides46 may be used to guide and align the reticle 12 when the reticle 12 isseated on the base 32. The reticle 12 may rest on and be supported bythe reticle supports 48 located in each of the four corners 38 of thebase 32. The reticle supports 48 may be in the form of a spherical ballsor protrusions that extend away from the first major surface 34 of thebase 32. In some embodiments, the reticle supports 48 may be located anequal distance between each of the reticle guides 46 of a pair ofreticle guides 46. Additionally, the reticle supports 48 may beconfigured such that they suspend the reticle 12 at a predefined heightabove the major surface 34 of the inner pod base 32 creating a gapbetween the reticle and the surface 34 of the inner pod base. In somecases, the gap is dimensioned to define a diffusion layer or diffusionbarrier between the reticle 12 and the base 32. The diffusion barrierinhibits particles from migrating into the gap.

The inner pod cover 26 is configured to mate with the inner pod base 32to define a sealed environment. The inner pod cover 26 has a size andshape generally corresponding to the size and shape of the inner podbase 32. In some cases, the inner pod cover 26 may include a pluralityof protrusions or pins 54 sized and configured to be received by aplurality of notches 56 defined in an edge of the base 32. The pins 54and notches 56 cooperate together to guide and align the cover 26 overthe base 32 and also to retain the cover 26 in position when the cover26 is engaged with the base 32.

The inner pod cover 26 also incorporates one or more reticle retainers60, which will be described in greater detail herein. The reticleretainers 60 help to reduce or prevent movement of the reticle that maygenerate particles. The reticle retainers are incorporated into theinner pod cover 26 such that when the inner pod cover 26 is closed andis contained within the outer pod, the reticle retainers constrainhorizontal or side to side movement of the reticle in an X and Y planesand also movement in the Z-direction. The reticle retainers 60 engagethe side and/or or edge of the reticle in response to a downward forceapplied to the retainer in the Z-direction by a corresponding structureprovided on the inner surface of the outer pod cover. In manyembodiments, the inner pod cover 26 includes at least two reticleretainers 60. For example, in one embodiment, the inner pod cover 26includes four reticle retainers 60. The number and location of thereticle retainers 60 may vary depending upon the size of the overall pod10 and the load to be applied to the reticle 12 contained within theinner pod.

In addition to the reticle retainers 60, the inner pod cover 26 caninclude one or more filters 64 including a filter media containedtherein for maintaining and controlling the microenvironment within theinner pod when the inner pod cover 26 is engaged with the inner pod base32.

FIG. 4 is a close up, cross-section view of a reticle retainer 60according to an embodiment of the disclosure. In some cases, up to foursuch reticle retainers 60 can be located at different regions of thepod. The reticle retainer 60A includes a pin 68 extending through a bore72 provided in the cover 26. The pin 68 can be attached to a resilientmember 76 which is accessible on the outer surface of the cover 26. Theresilient member 76 can be an elastomeric disk that is configured tobias the pin 68 in a retracted position. In the retracted position, thepin 68 is positioned upwards and away from the reticle 12 in the absenceof a downward force applied to the pin 68 in the Z-direction. The diskforming the resilient member 76 may form a seal between the pin 68 andthe bore 72 to prevent particulate matter from entering the inner pod.

The pin 68 includes two recesses 78. A spherical member or ball 80 a, 80b is received in each of the recesses 78. The spherical members or balls80 a, 80 b can be formed from a metal, metal alloy, ceramic or polymericmaterial. A first ball 80 a can be positioned at an angle relative tothe second ball 80 b such when the reticle retainer 60A engages thereticle 12, the first ball 80 a is in contact with an upper surface 82of the reticle 12 of the reticle and the second ball 80 b is in contactwith a side surface 84 of the reticle 12. The reticle retainer 60Aengages the reticle 12 in response to the application of a downwardforce provided by a corresponding structure provided on the innersurface of the outer pod cover. Contacting the upper surface 82 of thereticle 12 while at the same time contacting the side surface 84 of thereticle, constrains the reticle 12 at its edge. Because the reticleretainer 60A engages an edge 84 of the reticle 12, side to side orhorizontal movement in the X and Y planes can be prevented or reduced.In addition, the applied load in the Z direction can be reduced.

FIG. 5 a close up, cross-sectional view of another reticle retainer 160.In some cases, up to four such reticle retainers 160 can be located atdifferent regions of the pod to provide up to four different points ofcontact. Similar to the embodiment discussed herein with reference toFIG. 4, the reticle retainer 160 includes a block or pin 168 extendingthrough a bore 172 provided in the cover 26. The pin 168 can be attachedto a resilient member 176 which is accessible on the outer surface ofthe cover 26. The resilient member 176 can be an elastomeric disk thatis configured to bias the pin 168 in a retracted position. In theretracted position, the pin 168 is positioned upwards and away from thereticle 12. The disk forming the resilient member 176 may form a sealbetween the pin 168 and the bore 172 to prevent particulate matter fromentering the inner pod.

A reticle contact member 180 is coupled to the pin 168. The reticlecontact member 180 can be formed from stainless steel or TORLON and hasan angled contact surface 182. In some cases, the edge 184 of thereticle 12 can be chamfered or beveled. The angled contact surface 182of the contact member 180 is configured to contact and constrain an edge184 of the reticle 12 when a downward force is applied to the pin 168 tomove the pin in the Z-direction. The reticle retainer 160 engages thereticle 12 in response to the application of a downward force providedby a corresponding structure provided on the inner surface of the outerpod cover. Because the reticle retainer 160 engages an edge 184 of thereticle 12, side to side or horizontal movement in the X and Y planescan be prevented or reduced. In addition, the applied load in the Zdirection can be reduced.

FIG. 6A is a close-up view of another reticle retainer 260 provided onan inner surface 28 of an inner pod cover 26 in accordance with anotherembodiment of the disclosure. In some cases, up to four such reticleretainers 260 can be located at different regions of the pod to provideup to four different points of contact. FIG. 6B is a schematic,cross-sectional view of the reticle retainer 260 shown in FIG. 6A. Asshown in FIGS. 6A and 6B, the reticle retainer 260 includes a springflexure or spring arm 262. The spring arm 262 is secured to the innersurface of the cover 26 using a screw 264 or other fastener. The springarm 262 is configured to flex downward in a Z-direction when contactedby the pin 268. The spring arm 262 is configured to flex downward from arelaxed state in which no force is applied to a second state in which adownward force is applied, placing the spring arm 262 under sometension. The spring arm 262 is biased to its relaxed state and movesonly when a downward force is applied to it by the pin 268. The springarm 262 can be made of stainless steel, titanium, titanium alloy,NITINOL which has shape memory properties, and selected elastomericpolymers.

The pin 268 is similar to the pins 68 and 168 described herein. The pin268 is positioned upwards and away from the reticle 12 in the absence ofa downward force applied to the pin 268 in the Z-direction. A downwardforce can be applied to the pin 268 by a corresponding structureprovided on the inner surface of the outer pod cover. In operation, thepin 268 contacts a distal end 270 of the spring arm 262, causing thespring arm 262 to move from its relaxed state to a second state in whichthe spring arm 262 contacts an edge 272 of the reticle 12. In somecases, the edge 272 of the reticle 12 can be chamfered or beveled.Because the reticle retainer 260 engages an edge 272 of the reticle 12,side to side or horizontal movement in the X and Y planes can beprevented or reduced. In some cases, separate reticle restraints may beprovided on the inner surface of the top cover 26 to constrain verticalmovement of the reticle in the Z direction. However, because the reticleretainer 260 restricts lateral movement in the X and Y direction, theload applied in the Z direction can be reduced.

FIG. 7 shows a schematic view of an embodiment in which the reticleretainer(s) 360 are coupled to a base 362 of an inner pod as describedherein. In some cases, up to four such reticle retainers 360 can belocated at different regions of the pod. FIG. 7 shows a first reticleretainer 360 a in first position the first reticle retainer 360 a is notin contact with a side of the reticle. Additionally, FIG. 7 shows asecond reticle retainer 360 b in a second position in which the secondreticle retainer 360 b contacts a side 372 of the reticle 12. Similar tothe embodiment described with reference to FIGS. 6A and 6B, each of thereticle retainers 360 a, 360 b include a spring flexure or spring arm364. The spring arms 364 can be secured to the inner surface of the base362 using a screw 366 or other fastener. The spring arms 364 areconfigured to flex downward in a Z-direction when contacted by a pin orother structure secured to the inner pod cover as discussed herein. Thespring arm 364 is configured to flex downward from a relaxed state inwhich no force is applied to a second state in which a second state isapplied, placing the spring arm 364 under some tension. The spring arm364 is biased to its relaxed state and moves only when a downward forceis applied to it by a pin or other structure. The spring arm 364 can bemade of stainless steel, titanium, titanium alloy, NITINOL which hasshape memory properties, and selected elastomeric polymers. In somecases, separate reticle restraints may be provided on the inner surfaceof the top cover 26 to constrain vertical movement of the reticle in theZ direction. However, because the reticle retainer 360 restricts lateralmovement in the X and Y directions, the load applied in the Z directioncan be reduced.

FIG. 8 shows yet another reticle retainer 460. In some cases, up to foursuch reticle retainers 460 can be located at different regions of thepod to provide up to four different points of contact. As shown in FIG.8, when the cover 26 is seated on the base 32, a stationery retainingpin or block 468 that contacts the reticle retainer 460 to move thereticle retainer into contact with a side wall 472 of the reticle 12.The reticle retainer 460 is coupled to the cover 26 and is configured topivot from a first position in which there is no to contact with thereticle to a second position in which the retainer 460 contacts thereticle 12 from the side as shown in FIG. 8. In some cases, separatereticle restraints provided on the inner surface of the top cover 26 maybe provided to constrain vertical movement of the reticle in the Zdirection. However, because the reticle retainer 460 restricts lateralmovement in the X and Y directions, the load applied in the Z directioncan be reduced.

FIG. 9A shows a partial view of the inside of the inner pod cover 26.The inner pod 26 includes a recess or socket 482 for receiving thereticle retainer 460. As shown in FIG. 9B, the reticle retainer 460includes a body 490 and a pivot arm 492. The pivot arm 492 is configuredto be received in the grooves defined within the socket 482 such thatthe body 490 is capable of pivoting from a first position to a secondposition along a pivot axis defined by the pivot arm 492. In some cases,the reticle retainer 460 relies on gravity to stay in the firstposition. The reticle retainer is configured to move from the firstposition to the second position upon contact by the pin 468. In othercases, the reticle retainer 460 is spring loaded and is biased to afirst position. In either embodiment, contact with the pin 468 causesthe reticle retainer 460 to move from its first position to a secondposition where it contacts a sidewall 472 of the reticle.

FIGS. 10A-10D show the reticle retainer 460 in operation. As the cover26 is brought into contact with the base 32, the pin 468 begins tocontact an edge of the retainer 460, as shown in FIG. 10A. Upon furthercontact by the pin 468, the reticle retainer 460 begins to contact aside wall 472 of the reticle 12 and minimizes the gap between thereticle 12 and the pin 468. As shown in FIG. 10C, at a minimum gapdistance defined between the pin 468 and the reticle 12, the reticleretainer 460 can be received in a slot defined in the socket 482. At amaximum distance between the pin 468 and the reticle 12, as shown inFIG. 10D, the reticle retainer 460 is not received in the slot; however,contact is maintained between the retainer 460 and the side wall 472 ofthe reticle.

FIGS. 11-12C show various views of yet another embodiment of a reticleretainer 560. In some cases, up to four such reticle retainers 560 canbe located at different regions of the pod to provide up to fourdifferent points of contact. As best seen in FIG. 11, the reticleretainer 560 is configured to contact a top surface 502 and a side wall572 of a reticle 12. Because the reticle retainer 560 contacts the sidewall 572 of the reticle 12, the load applied to the top surface 502 canbe reduced, and movement of the reticle is constrained in the X, Y, andZ directions.

As shown in FIG. 11, the reticle retainer 560 includes a body 562, anarm 564 extending away from the body, and a resilient member 576, suchas diaphragm. In some cases, both the arm 564 and the resilient member576 are accessible on the outer surface of the cover 26. In thisembodiment, the reticle retainer body 562 is biased in a retractedposition by the spring force of the arm 564. Application of a downwardforce to the arm 564, causes the body 562 to move in the Z-direction.

The reticle retainer body 562 includes two recesses 578. A reticlecontact member or ball 580 a, 580 b is received in each of the recesses578. The reticle contact members or balls 580 a, 580 b can be formedfrom a metal, meal alloy, ceramic or polymeric material. A first ball580 a can be positioned at an angle relative to the second ball 580 bsuch when the reticle retainer 560 engages the reticle 12, the firstball 580 a is in contact with an upper surface 502 of the reticle 12 ofthe reticle and the second ball 580 b is in contact with a side wall 572of the reticle 12. The reticle retainer 560 engages the reticle 12 inresponse to the application of a downward force provided by acorresponding structure provided on the inner surface of the outer podcover. Application of a downward force to the arm 564 causes the firstreticle contact member 580 a to contact the top surface 502 of thereticle 12 followed by the contact the body 562 to pivoting slightlyinward toward the reticle 12 to bring the second contact member 580 binto contact with the sidewall 572 of the reticle 12. Contact at the topsurface 502 and the sidewall 572 of the reticle 12 constrains movementof the reticle 12 in the X, Y and Z directions.

FIG. 13 shows an inner pod 600. The inner pod 600 includes an inner podcover 602 configured to mate with the inner pod base 604 to define asealed environment. A reticle can be contained within the sealedenvironment. The inner pod cover 602 has a size and shape generallycorresponding to the size and shape of the inner pod base 604. In somecases, the inner pod cover 602 may include a plurality of protrusions orpins 608 sized and configured to be received by a plurality ofcorresponding recesses or notches 609 defined in an edge of the base604. The pins 608 and notches 609 cooperate together to guide and alignthe cover 602 over the base 604, and also to retain the cover 602 inposition when the cover 602 is engaged with the base 604.

The inner pod cover 602 also incorporates one or more sets of reticleretainers 610 and 614. The reticle retainers 610 and 614 help to reduceor prevent movement of the reticle that may generate particles. The setsof reticle retainers 610 and 614 are incorporated into the inner podcover 602 such that when the inner pod cover 602 is closed the reticleretainers collectively constrain horizontal or side to side movement ofthe reticle in the X and Y planes in addition to the Z-direction. Thereticle retainers 610 engage the side and/or an edge of the reticle inresponse to a downward force applied to the retainer in the Z-directionby a corresponding structure provided on the inner surface of the outerpod cover. The reticle retainers 614 contact a top surface of thereticle retainer in response to a downward force applied by acorresponding structure provided on the inner surface of the outer podcover. However, because reticle retainers 610 constrain the reticle fromthe side, the amount of force applied by reticle retainers 614 to thetop surface of the reticle can be reduced. In addition, when the innerpod 600 is closed and is contained within an outer pod, the reticleretainer 614 contact a top surface of the reticle 12 prior to the sidereticle retainers 610 contacting a side surface and/or an edge of thereticle 12. Providing initial contact with a top surface of the reticle12 stabilizes the reticle and prevents it from shifting in the X and/orY plane prior to being restrained by the side reticle retainers 610.

The number and location of the reticle retainers 610, 614 can varydepending upon the size of the overall pod and the load to be applied tothe reticle contained within the inner pod. In some cases, it may beuseful to combine reticle retainers configured to contact a top surfaceof the reticle with reticle retainers configured to contact a reticlefrom a side or an edge of the reticle. In other cases, the inner podcover may include reticle retainers configured to contact a side or anedge of the reticle and may eliminate reticle retainers configured tocontact a top surface of the reticle. In some embodiments, as shown inFIG. 13, the inner pod cover 602 can include two pairs of reticleretainers, each reticle retainer configured to contact the reticle fromthe side and at least one pair of reticle retainers wherein each reticleretainer is configured to contact a top surface of the reticle. Eachpair of reticle retainers 610 configured for side contact are positionedon the inner pod cover 602 such that they work together to constrain acorner of the reticle from movement in the X and Y planes.

In addition to the reticle retainers 610 and 614, the inner pod cover602 can include one or more filters including a filter media containedtherein for maintaining and controlling the microenvironment within theinner pod when the inner pod cover 602 is engaged with the inner podbase 604.

FIGS. 14A and 14B show different views of a portion of a reticleretainer 610, configured to restrain the reticle from a side of thereticle. As can be seen in FIGS. 14A and 14B, the reticle retainer 610includes a reticle contact member 616, a resilient member 618 and a cap620, all of which are accessible from outside the inner pod cover 602.The reticle contact member 616 and the resilient member 618 are retainedin place by the cap 620 which is secured to the inner pod cover 602 byone or more fasters such as, for example, a pair of screws. Theresilient member 618 can be an elastomeric disk or diaphragm configuredto bias the reticle contact member 616 to a retracted or non-contactposition. In addition, as discussed previously herein, the disk formingthe resilient member 618 can act as a seal and may help to preventparticulate matter from entering the inner pod. In the retractedposition, the reticle contact member 616 is positioned away from and outof contact with the reticle 12. Both the resilient member 618 and thereticle contact member 616 are configured to respond to the applicationof a downward force in the Z-direction permitting the reticle contactmember 616 to move from a first, retracted position in which the reticlecontact member 616 is not in contact with the reticle to a secondposition in which the reticle contact member 616 contacts a side of thereticle housed within the inner pod. In some cases, the inner pod cover602 can also include one or more recesses 622 for receiving a portion ofthe reticle contact member 616. A portion of the reticle contact member616 is received in the recess 622 upon application of a downward forcein the Z-direction to the reticle contact member 616. The recess 622provides a stabilizing force to the reticle contact member 616 toprevent the reticle contact member 616 from sliding in the X andY-planes.

FIGS. 15A-15C show different views of a reticle contact member 616. Thereticle contact member 616 can be a single unitary piece made from apolymer, polymer blend, metal or metal alloy. The reticle contact member616 can be machined or injection molded depending upon the material fromwhich it is made. In some cases, as seen, the reticle contact member 616includes a laterally extending arm 626 including at least one downwardlyextending finger 628. Additionally, the reticle contact member 616includes a downwardly extending leg 630 having a smooth outwardlyextending face 632 configured to contact a side of a reticle. Each ofthe fingers 628 are configured to be received in and apply a downwardforce to a corresponding recess 622 formed in the inner pod cover 602for that purpose. In some cases, as shown FIGS. 15A-15C, each of thefingers 628 include an angled or beveled edge. The angled or bevelededge provided on each of the fingers 628 is designed to increase theamount of friction between the fingers 628 and the surfaces of therecess 622 such that the reticle contact member 616 is resistant to sideto side movement in the X and Y planes. This interaction between thefingers 628 and the surfaces of the recess may reduce the likelihood ofthe leg 630 sliding away from the reticle. In some cases, as shown, theleg 630 can include a groove 634 for interacting with a retaining theresilient member 618.

FIGS. 16A and 16B show top and bottom views of the cap 620. In use, thecap 620 is disposed over and in contact with the reticle contact member616 and the resilient member 618. The cap 620 includes a bracket orcross-brace member 634 that contacts and retrains side to side movementof the reticle contact member 616 in the X and Y planes, as well aslimits any potential upward and downward movement of the reticle contactmember 616 in the Z-direction. In some cases, the bracket 634 has a Yshape or is wishbone shaped, although other configurations may bereadily recognized by those of skill in the art. In some cases, the cap620 can includes a circular ridge 638 that contacts and applies apressure to the resilient member 618 and one or more apertures toreceive one or more corresponding fasteners to secure the cap 620 to theinner pod cover 602.

FIGS. 17A and 17B show cross-sectional views of the inner pod 600including the reticle retainer 610. FIG. 17A shows the reticle retainer610 in a first, non-contact position and FIG. 17B shows the reticleretainer 610 in a second, contact position in which the leg 630 of thereticle contact member 616 has been brought into contact with a sidesurface 644 of the reticle 12 upon application of a downward force inthe Z-direction to the arm 626. Upon application of a downward force tothe arm 626 of the reticle contact member 616, the reticle contactmember 616 pivots or rotates about a first axis of rotation 646, causingthe fingers 628 to move downward to be received in the recess 622 andalso causing the leg 630 to pivot forward towards the side surface 644.Rotation about the first axis of rotation 646 ceases when the leg 630contact the side surface of the reticle 644 as shown in FIG. 17B. Asecond axis of rotation 648 is created by the reticle 12 pushing back onthe leg 630. However, the return action of the reticle 12 pushing backon the leg 630 action causes additional force to be placed on thefingers 628 received in the recess 622, further strengthening andstabilizing the point of contact between the reticle contact member 616and the reticle 12. In addition, the axis of rotation 646 is flexible,and changes from rotation axis 646 to rotation axis 648. This shift orchange in the rotation axis from the first axis of rotation 646 to thesecond axis of rotation 648 is provided by the resilient member 618. Theresilient member 618 provides a sufficient amount of flexibility suchthat the first axis of rotation 646 can shift in the X plane when theleg 630 contacts the side surface 644 of the reticle 12 at the secondrotational axis 648. In response to contact between the leg 630 and theside surface 644, the resilient member 618 flexes to help main sidecontact between the leg 630 and the reticle 12 preventing movement ofthe reticle 12 in the X and/or Y plane. Referring back to FIG. 13,constraining the reticle 12 in the X and Y planes by contacting the sidesurface 644 of the reticle 12 may reduce amount of the load need in theZ direction which may be applied by additional reticle retainers 614.

FIG. 18 shows an inner pod 700 according to another embodiment of thedisclosure. The inner pod 700 includes an inner pod cover 702 configuredto mate with the inner pod base 704 to define a sealed environment. Areticle can be contained within the sealed environment. The inner podcover 702 has a size and shape generally corresponding to the size andshape of the inner pod base 704. In some cases, the inner pod cover 702may include a plurality of protrusions or pins 708 sized and configuredto be received by a plurality of corresponding recesses or notches 709defined in an edge of the base 704. The pins 708 and notches 709cooperate together to guide and align the cover 702 over the base 704.Additionally, the pins 708 and notches 709 retain the cover 702 inposition when the cover 702 is engaged with the base 704.

The inner pod cover 702 also incorporates one or more sets of reticleretainers 710 and 714. The reticle retainers 710 and 714 help to reduceor prevent movement of the reticle that may generate particles. Thereticle retainers 710 and 714 are incorporated into the inner pod cover702 such that when the inner pod cover 702 is closed the reticleretainers collectively constrain horizontal or side to side movement ofthe reticle in the X and Y planes in addition to the Z-direction. Thereticle retainers 710 engage the side and/or or edge of the reticle inresponse to a downward force applied to the retainer in the Z-directionby a corresponding structure provided on the inner surface of the outerpod cover. The reticle retainers 714 contact a top surface of thereticle retainer in response to a downward force applied by acorresponding structure provided on the inner surface of the outer podcover. However, because reticle retainers 710 constrain the reticle fromthe side, the amount of force applied by reticle retainers 714 to thetop surface of the reticle can be reduced. In addition, when the innerpod 700 is closed and is contained within an outer pod, the reticleretainer 714 contact a top surface of the reticle 12 prior to the sidereticle retainers 710 contacting a side surface and/or an edge of thereticle 12. Providing initial contact with a top surface of the reticle12 stabilizes the reticle and prevents it from shifting in the X and/orY plane prior to being restrained by the side reticle retainers 710.

The number and location of the reticle retainers 710, 714 can varydepending upon the size of the overall pod and the load to be applied tothe reticle contained within the inner pod. In some cases, it may beuseful to combine reticle retainers configured to contact a top surfaceof the reticle with reticle retainers configured to contact a reticlefrom a side or an edge of the reticle. In other cases, the inner podcover 702 may include reticle retainers configured to contact a side oran edge of the reticle and may eliminate reticle retainers configured tocontact a top surface of the reticle. In some embodiments, as shown inFIG. 18, the inner pod cover 702 can include two pairs of reticleretainers 710, each configured to contact the reticle from the side andat least one pair of reticle retainers 714 configured to contact a topsurface of the reticle. In some cases, each pair of reticle retainers710 configured for side contact are positioned on the inner pod cover702 such that they work together to constrain a corner of the reticlefrom movement in the X and Y planes.

In addition to the reticle retainers 710 and 714, the inner pod cover702 can include one or more filters including a filter media containedtherein for maintaining and controlling the microenvironment within theinner pod when the inner pod cover 702 is engaged with the inner podbase 704.

FIG. 19 shows different views of a portion of a reticle retainer 710,configured to restrain the reticle from a side of the reticle. As can beseen in FIG. 19, the reticle retainer 710 includes a reticle contactmember 716, a resilient member 718 (shown in FIGS. 23A and 23B) and acap 720, all of which are accessible from outside the inner pod cover702. The reticle contact member 716 and the resilient member 718 areretained in place by the cap 720 which is secured to the inner pod cover702 by one or more fasters such as, for example, a screw. The resilientmember 718 can be an elastomeric disk or diaphragm configured to biasthe reticle contact member 716 to a retracted or non-contact position.In addition, as discussed previously herein, the disk forming theresilient member 718 can act as a seal and may help to preventparticulate matter from entering the inner pod. In the retractedposition, the reticle contact member 716 is positioned away from and outof contact with the reticle. Both the resilient member 718 and thereticle contact member 716 are configured to respond to the applicationof a downward force in the Z-direction permitting the reticle contactmember 716 to move from a first, retracted position in which the reticlecontact member 716 is not in contact with the reticle to a secondposition in which the reticle contact member 716 contacts a side of thereticle housed within the inner pod. In some cases, the inner pod cover702 can also include one or more recesses 722 for receiving a portion ofthe reticle contact member 716. A portion of the reticle contact member716 is received in the recesses 722 upon application of a downward forcein the Z-direction to the reticle contact member 716. The recesses 722provides a stabilizing force to the reticle contact member 716 toprevent the reticle contact member 716 from sliding side to side the Xand Y-planes.

FIGS. 20A and 20B show different views of a reticle contact member 716.The reticle contact member 716 can be a single unitary piece made from apolymer, polymer blend, metal or metal alloy. The reticle contact member716 can be machined or injection molded depending upon the material fromwhich it is made. In some cases, as seen, the reticle contact member 716includes a laterally extending arm 726 and a cross member 728 that formsa T-shape with the laterally extending arm 726. The cross member 728includes a first downwardly extending shoulder 730 a that is spacedapart from a second downwardly extending shoulder 730 b. In some cases,the downwardly extending shoulders 730 a, 730 b extend along an entirewidth of the cross member 728, but this is not required. In other cases,the downwardly extending shoulders 730 a, 730 b can extend fromtwenty-five percent to seventy five percent of the width of the crossmember 728. Additionally, the reticle contact member 716 includes adownwardly extending leg 732 having a smooth outwardly extending face733 configured to contact a side of a reticle.

Each of the shoulders 730 a, 730 b are configured to be received in andapply a downward force to a corresponding recess 722 formed in the innerpod cover 702 for that purpose. In some cases, as shown FIGS. 20A and20B, each of the shoulders 730 a, 730 b include an angled or bevelededge. The angled or beveled edge provided on each of the shoulders 730a, 730 b is designed to increase the amount of friction between theshoulders 730 a, 730 b and the surfaces of the recesses 722 such thatthe reticle contact member 716 resists side to side movement in the Xand Y planes. This interaction between the shoulders 730 a, 730 b andthe surfaces of the recesses 722 may reduce the likelihood of the leg732 sliding away from the reticle when in contact with the reticle. Insome cases, as shown, the leg 732 can include a groove 735 forinteracting with a retaining the resilient member 718.

FIGS. 21A and 21B show top and bottom views of a cap 720A according toone embodiment. In use, the cap 720A is disposed over and in contactwith the reticle contact member 716 and the resilient member 718. Thecap 720A includes two generally circular or C-shaped bracket members 736that contact and retrain side to side movement of the two reticlecontact members 716 that are located adjacent one another. In somecases, as best viewed in FIG. 21B, each of the bracket members 736includes a circular ridge 738 that contacts and applies a pressure tothe resilient member 718. Additionally, the cap includes an aperture 740for receiving a fastener such as a screw that is spaced apart from eachof the bracket member 736. The bracket members 736 and the aperture 740are positioned relative to one another such that a triangle can bedefined by drawing lines through each of their center points. FIGS. 22Aand 22B show a similar cap 720B. The primary different is that the cap720B is more solid than the cap 720A due to differences inmanufacturing. One of ordinary skill in the art will readily recognizethat the function of the cap 720B and the relationship between the partsremains the same.

FIGS. 23A and 23B show cross-section views of the inner pod 700including the reticle retainer 710. FIG. 23A shows the reticle retainer710 in a first, non-contact position and FIG. 23B shows the reticleretainer 710 in a second, contact position in which the leg 732 of thereticle contact member 716 has been brought into contact with a sidesurface 744 of the reticle 12 upon application of a downward force inthe Z-direction to the arm 726 and/or cross member 728. Upon applicationof a downward force to the arm 726 and/or cross-member 728 of thereticle contact member 716, the reticle contact member 716 pivots orrotates about a first axis of rotation 746, causing the shoulders 730 a,730 b, of which only 730 a is visible in the figures, to move downwardto be received in the recesses, and also causing the leg 732 to pivotforward towards the side surface 744 of the reticle 12. Rotation aboutthe first axis of rotation 746 ceases when the leg 732 contacts the sidesurface 744 of the reticle 12 as shown in FIG. 23B. A second axis ofrotation 748 is created by the reticle 12 pushing back on the leg 732.However, the return action of the reticle 12 pushing back on the leg 732action causes additional force to be placed on the shoulders 730 a, 730b received in the recess 722, further strengthening and stabilizing thepoint of contact between the reticle contact member 716 and the reticle716. In addition, the axis of rotation 746 is flexible, and changes fromrotation axis 746 to rotation axis 748. This shift or change in therotation axis from the first axis of rotation 746 to the second axis ofrotation 748 is provided by the resilient member 718. The resilientmember 718 provides a sufficient amount of flexibility such that thefirst axis of rotation 746 can shift in the X plane when the leg 732contacts the side surface 744 of the reticle 12 at the second rotationalaxis 748. In response to contact between the leg 732 and the sidesurface 744, the resilient member 718 flexes to help main side contactbetween the leg 732 and the reticle 12 preventing movement of thereticle 12 in the X and/or Y plane. Referring back to FIG. 18,constraining the reticle 12 in the X and Y planes by contacting the sidesurface 744 of the reticle 12 may reduce amount of the load need in theZ direction which may be applied by additional reticle retainers 714.

FIG. 24 is partial cross-sectional view showing the inner pod 700contained within an outer pod 800 forming a dual pod assembly. The outerpod 800 includes an outer pod cover 802 and an outer pod base 804. Theouter pod cover 802 includes at least one contact member or pad 806that, when the inner pod 700 is contained within the outer pod, contactsand applies a downward pressure in the Z-direction to the arm 726 and/orcross member 728 of the reticle contact member 716. The number ofcontact members or pads 806 incorporated into the outer pod cover 802corresponds in a one to one manner with the number of reticle contactmember 716. The downward application force in the Z-direction to the arm726 and/or cross member 728 causes the reticle contact member to 716 toengage a side surface 744 of the reticle 12 constraining and/orpreventing the reticle 12 from side to side movement in the X and Yplanes. Referring back to FIG. 18, constraining the reticle 12 in the Xand Y planes by contacting the side surface 744 of the reticle 12 mayreduce amount of the load need in the Z direction which may be appliedby additional reticle retainers 714.

FIG. 25 is a simplified view of the inner pod 700 shown in FIG. 19showing the relative locations of the locating pins 708 a, 708 b, 708 c,and 708 d to one another. Each of the pins 708 a-708 d are locatedadjacent a corner 712 of the inner pod 700. As shown in FIG. 25 and asdescribed previously herein, each of the pins 708 a-708 d are receivedin a corresponding recesses defined in the base 704. For example, as canbe seen in FIG. 25, pin 708 a is received in corresponding recess 709 aand pin 708 c is received in recess 709 c. As described previouslyherein, the corresponding pins and recesses cooperate together to guideand align the cover 702 over the base 704 and also to retain the cover702 in position when the cover 702 is engaged with the base 704.Additionally, the location of the pins and recesses relative to oneanother add in resisting movement of the cover 702 relative to the base704 in the X and Y planes and also help to resist any rotationalmovement of the cover 702 relative to the base.

As can be seen in FIG. 25, a first set of pins 708 a, 708 b and theircorresponding recesses, of which only recess 709 a is visible, arelocated in a first vertical plane defined by a first axis 1. At least athird pin 708 c and corresponding recess 709 c is located in a secondvertical plane defined by a second axis M. The fourth pin 708 d and itscorresponding recess is optional. In some cases, the second verticalplane defined by the second axis m bisects the first vertical planedefined by the first axis 1 at an angle α ranging from about 60 degreesto about 110 degrees, and more particularly, at an angle α ranging fromabout 60 degrees to about 90 degrees. In other cases, the secondvertical plane defined by the second axis m bisects the first verticalplane defined by the first axis 1 at an orthogonal or 90 degree angle.Placing a third pin 708 c and recess 709 c on an axis or in a plane thatis on-angle or in some cases, orthogonal, relative to a first axis orplane defined by a first set of pins limits movement of the cover 702relative to the base in both direction of the l axis. In addition, thewidth of the pin relative to the width of the recess is selected suchthat when the cover 702 is seated on the base 704 and the pin, such aspin 708 a, is received in a corresponding recess, such as 709 a, thecover 702 is resistant to rotational movement. This resistant tomovement in the X and Y planes of the cover 702 relative to the base 704may also be accomplished by placing the three pins 708 a, 708 b, and 708c and their corresponding recesses on-center relative to one another.

FIGS. 26-29C relate to yet another embodiment of the disclosure. FIG. 26is a perspective view of an inner pod 800 including one or more reticleretainers 810 according to still other embodiments. The inner pod 800includes an inner pod cover 802 configured to mate with the inner podbase 804 to define a sealed environment. A reticle can be containedwithin the sealed environment. The inner pod cover 802 has a size andshape generally corresponding to the size and shape of the inner podbase 804. In some cases, the inner pod cover 802 may include a pluralityof protrusions or pins sized and configured to be received by aplurality of corresponding recesses or notches defined in an edge of thebase 804. The pins and notches cooperate together to guide and align thecover 802 over the base 804, and also to retain the cover 802 inposition when the cover 802 is engaged with the base 804.

As shown in FIG. 26, the inner pod cover 802 also incorporates one ormore pairs of reticle retainers 810. The reticle retainers 810 help toreduce or prevent movement of the reticle that may generate particles.The number and location of the reticle retainers 810 can vary dependingupon the size of the overall pod and the load to be applied to thereticle contained within the inner pod. The reticle retainers 810 areincorporated into the inner pod cover 802 such that when the inner podcover 802 is closed the reticle retainers collectively constrainhorizontal or side to side movement of the reticle in the X and Y planesin addition to the Z-direction. Each reticle retainer is 810 isconfigured to contact a side surface of the reticle. Each pair ofreticle retainers 810 is located on the inner pod cover 802 such thatthe two reticle reticle retainers 810 work together to constrain acorner of the reticle from movement in the X and Y planes. In someembodiments, as shown, the reticle retainers 810 engage the side of thereticle in response to a downward force applied to the retainer in theZ-direction by a corresponding structure provided on the inner surfaceof the outer pod cover. Unlike previous embodiments described herein,the reticle retainers 810 do not intentionally contact a top surface ofthe reticle.

FIGS. 27 and 28 are different cross-sectional views of the inner podincluding a reticle retainer 810 and FIGS. 29A-29C are different viewsof an individual reticle retainer 810. Each reticle retainer 810includes an arm 814 and a main body portion 816. The arm extends in adirection that is perpendicular to the direction in which the main bodyportion 816 extends. For example, in some cases, the arm 814 extends inan X or Y direction and the main body portion 816 extends in aZ-direction. The main body portion 816 contacts the side surface 818ofthe reticle 12 in response to application of a downward force in theZ-direction to the arm 814 by a corresponding structure provided on theinner surface of the outer pod cover. Upon side contact, some centeringof reticle will occur, but force during sliding will be minimal.Friction between the reticle and the reticle retainers also limitsmotion of the reticle in the X and Y direction during transit. In somecases, as shown in FIG. 27, the main body port 816 can include ashoulder portion 820 that is positioned above a top surface of thereticle to limit movement of the reticle in the Z-direction asnecessary. The shoulder portion 820 is not intended to contact a topsurface of the reticle 12. Rather, the shoulder portion 820 limitsmovement of the reticle 12 in the Z direction as necessary in responseto a shock event. Additionally, the reticle retainer 810 can include aseal 824 that surrounds the main body portion 816, and which may help toprevent particulate matter from entering the inner pod.

Having thus described several illustrative embodiments of the presentdisclosure, those of skill in the art will readily appreciate that yetother embodiments may be made and used within the scope of the claimshereto attached. Numerous advantages of the disclosure covered by thisdocument have been set forth in the foregoing description. It will beunderstood, however, that this disclosure is, in many respect, onlyillustrative. Changes may be made in details, particularly in matters ofshape, size, and arrangement of parts without exceeding the scope of thedisclosure. The disclosure's scope is, of course, defined in thelanguage in which the appended claims are expressed.

What is claimed is:
 1. A reticle pod for holding a reticle comprising: abase configured to support a reticle thereon; a cover having a topsurface and configured to mate with the base; and one or more reticleretainers each including a reticle contact member configured to contacta side wall of a reticle to limit movement of the reticle, each reticlecontact member including an outwardly extending arm and a downwardlyextending leg that extends through the cover, wherein upon actuation ofthe arm, the downwardly extending leg is configured to move in adirection toward a side wall of a reticle.
 2. The reticle pod of claim1, wherein the reticle contact member limits movement of the reticle ina horizontal direction.
 3. The reticle pod of claim 2, wherein thereticle contact member limit movement in a vertical direction.
 4. Thereticle pod of claim 1, wherein the reticle contact member is furtherconfigured to contact a top surface of a reticle.
 5. The reticle pod ofclaim 1, further comprising one or more additional reticle retainersconfigured to contact a top surface of a reticle.
 6. The reticle pod ofclaim 1, wherein each of the one or more reticle retainers furthercomprises a resilient member, wherein the resilient member biases thereticle contact member in a non-contact position.
 7. The reticle pod ofclaim 6, wherein each of the one or more resilient member includes anelastomeric disk that encircles the downwardly extending leg.
 8. Thereticle pod of claim 1, wherein each of the one or more reticleretainers includes a cap secured to the cover.
 9. The reticle pod ofclaim 1, wherein the outwardly extending arm extends at least partiallyabove a top surface of the cover.
 10. The reticle pod of claim 1,wherein the outwardly extending arm comprises at least one downwardlyextending member.
 11. The reticle pod of claim 10, wherein the coverfurther comprises a recess configured to receive the at least onedownwardly extending member upon actuation of the outwardly extendingarm.
 12. The reticle pod of clam 10, wherein the reticle contact memberfurther includes a cross member that forms a T-shape with the outwardlyextending arm, the cross member having at least one downwardly extendingmember.
 13. The reticle pod of claim 1, wherein the downwardly extendingleg includes at least a first recess and a first contact member receivedin the first recess.
 14. The reticle pod of claim 13, wherein thedownwardly extending leg includes a second recess and a second contactmember received in the second recess, wherein the first contact memberis positioned at an angel relative to the first recess.
 15. The reticlepod of claim 1, wherein the reticle pod is contained within an outer podhaving an outer pod base and an outer pod cover configured to mate withthe outer pod base, the outer pod cover having an inner surface and atleast one contact pad extending from the inner surface such that itcontacts and actuates the outwardly extending arm of the reticle podcausing the downwardly extending leg to move in a direction toward theside wall of the reticle.
 16. A method of retaining a reticlecomprising: receiving a reticle on a base having features configured tosupport the reticle thereon; placing a cover on the base including thereticle to define an inner pod, the cover including one or more reticleretainers each including a reticle contact member, each reticle contactmember including an outwardly extending arm that is extends at leastpartially above the top surface of the cover and a downwardly extendingleg that extends through the cover; and limiting movement of thereticle.
 17. The method of claim 16, wherein limiting movement of thereticle comprises actuating the one or more reticle retainers to contacta side wall of the reticle to limit movement of the reticle in ahorizontal direction.
 18. The method of claim 16, wherein limitingmovement of the reticle further comprises actuating the one or morereticle retains to contact a top surface of the reticle to limitmovement of the reticle in a vertical direction.
 19. The method of claim16, further comprising enclosing the inner pod within an outer podincluding an outer pod cover and an outer pod base, the outer coverincluding one or more contact members provided on an inner surface,wherein when the inner pod is enclosed within the outer pod, eachcontact member contacts and applies a downward force to a correspondingreticle retainer of the one or more reticle retainers.